1 | /* $NetBSD: ext2fs_extents.c,v 1.3 2016/08/13 07:40:10 christos Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2010 Zheng Liu <lz@freebsd.org> |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
26 | * SUCH DAMAGE. |
27 | * |
28 | * $FreeBSD: head/sys/fs/ext2fs/ext2_extents.c 295523 2016-02-11 15:27:14Z pfg $ |
29 | */ |
30 | |
31 | #include <sys/cdefs.h> |
32 | __KERNEL_RCSID(0, "$NetBSD: ext2fs_extents.c,v 1.3 2016/08/13 07:40:10 christos Exp $" ); |
33 | |
34 | #include <sys/param.h> |
35 | #include <sys/systm.h> |
36 | #include <sys/resourcevar.h> |
37 | #include <sys/kernel.h> |
38 | #include <sys/file.h> |
39 | #include <sys/stat.h> |
40 | #include <sys/buf.h> |
41 | #include <sys/proc.h> |
42 | #include <sys/mount.h> |
43 | #include <sys/vnode.h> |
44 | #include <sys/signalvar.h> |
45 | #include <sys/kauth.h> |
46 | |
47 | #include <ufs/ufs/inode.h> |
48 | #include <ufs/ufs/ufsmount.h> |
49 | #include <ufs/ufs/ufs_extern.h> |
50 | |
51 | |
52 | #include <ufs/ext2fs/ext2fs.h> |
53 | #include <ufs/ext2fs/ext2fs_extents.h> |
54 | #include <ufs/ext2fs/ext2fs_extern.h> |
55 | |
56 | |
57 | |
58 | static bool |
59 | ext4_ext_binsearch_index(struct inode *ip, struct ext4_extent_path *path, |
60 | daddr_t lbn, daddr_t *first_lbn, daddr_t *last_lbn) |
61 | { |
62 | struct ext4_extent_header *ehp = path->ep_header; |
63 | struct ext4_extent_index *first, *last, *l, *r, *m; |
64 | |
65 | first = (struct ext4_extent_index *)(char *)(ehp + 1); |
66 | last = first + ehp->eh_ecount - 1; |
67 | l = first; |
68 | r = last; |
69 | while (l <= r) { |
70 | m = l + (r - l) / 2; |
71 | if (lbn < m->ei_blk) |
72 | r = m - 1; |
73 | else |
74 | l = m + 1; |
75 | } |
76 | |
77 | if (l == first) { |
78 | path->ep_sparse_ext.e_blk = *first_lbn; |
79 | path->ep_sparse_ext.e_len = first->ei_blk - *first_lbn; |
80 | path->ep_sparse_ext.e_start_hi = 0; |
81 | path->ep_sparse_ext.e_start_lo = 0; |
82 | path->ep_is_sparse = true; |
83 | return true; |
84 | } |
85 | path->ep_index = l - 1; |
86 | *first_lbn = path->ep_index->ei_blk; |
87 | if (path->ep_index < last) |
88 | *last_lbn = l->ei_blk - 1; |
89 | return false; |
90 | } |
91 | |
92 | static void |
93 | ext4_ext_binsearch(struct inode *ip, struct ext4_extent_path *path, daddr_t lbn, |
94 | daddr_t first_lbn, daddr_t last_lbn) |
95 | { |
96 | struct ext4_extent_header *ehp = path->ep_header; |
97 | struct ext4_extent *first, *l, *r, *m; |
98 | |
99 | if (ehp->eh_ecount == 0) |
100 | return; |
101 | |
102 | first = (struct ext4_extent *)(char *)(ehp + 1); |
103 | l = first; |
104 | r = first + ehp->eh_ecount - 1; |
105 | while (l <= r) { |
106 | m = l + (r - l) / 2; |
107 | if (lbn < m->e_blk) |
108 | r = m - 1; |
109 | else |
110 | l = m + 1; |
111 | } |
112 | |
113 | if (l == first) { |
114 | path->ep_sparse_ext.e_blk = first_lbn; |
115 | path->ep_sparse_ext.e_len = first->e_blk - first_lbn; |
116 | path->ep_sparse_ext.e_start_hi = 0; |
117 | path->ep_sparse_ext.e_start_lo = 0; |
118 | path->ep_is_sparse = true; |
119 | return; |
120 | } |
121 | path->ep_ext = l - 1; |
122 | if (path->ep_ext->e_blk + path->ep_ext->e_len <= lbn) { |
123 | path->ep_sparse_ext.e_blk = path->ep_ext->e_blk + |
124 | path->ep_ext->e_len; |
125 | if (l <= (first + ehp->eh_ecount - 1)) |
126 | path->ep_sparse_ext.e_len = l->e_blk - |
127 | path->ep_sparse_ext.e_blk; |
128 | else |
129 | path->ep_sparse_ext.e_len = last_lbn - |
130 | path->ep_sparse_ext.e_blk + 1; |
131 | path->ep_sparse_ext.e_start_hi = 0; |
132 | path->ep_sparse_ext.e_start_lo = 0; |
133 | path->ep_is_sparse = true; |
134 | } |
135 | } |
136 | |
137 | /* |
138 | * Find a block in ext4 extent cache. |
139 | */ |
140 | int |
141 | ext4_ext_in_cache(struct inode *ip, daddr_t lbn, struct ext4_extent *ep) |
142 | { |
143 | struct ext4_extent_cache *ecp; |
144 | int ret = EXT4_EXT_CACHE_NO; |
145 | |
146 | ecp = &ip->inode_ext.e2fs.i_ext_cache; |
147 | |
148 | /* cache is invalid */ |
149 | if (ecp->ec_type == EXT4_EXT_CACHE_NO) |
150 | return ret; |
151 | |
152 | if (lbn >= ecp->ec_blk && lbn < ecp->ec_blk + ecp->ec_len) { |
153 | ep->e_blk = ecp->ec_blk; |
154 | ep->e_start_lo = ecp->ec_start & 0xffffffff; |
155 | ep->e_start_hi = ecp->ec_start >> 32 & 0xffff; |
156 | ep->e_len = ecp->ec_len; |
157 | ret = ecp->ec_type; |
158 | } |
159 | return ret; |
160 | } |
161 | |
162 | /* |
163 | * Put an ext4_extent structure in ext4 cache. |
164 | */ |
165 | void |
166 | ext4_ext_put_cache(struct inode *ip, struct ext4_extent *ep, int type) |
167 | { |
168 | struct ext4_extent_cache *ecp; |
169 | |
170 | ecp = &ip->inode_ext.e2fs.i_ext_cache; |
171 | ecp->ec_type = type; |
172 | ecp->ec_blk = ep->e_blk; |
173 | ecp->ec_len = ep->e_len; |
174 | ecp->ec_start = (daddr_t)ep->e_start_hi << 32 | ep->e_start_lo; |
175 | } |
176 | |
177 | /* |
178 | * Find an extent. |
179 | */ |
180 | struct ext4_extent_path * |
181 | ext4_ext_find_extent(struct m_ext2fs *fs, struct inode *ip, |
182 | daddr_t lbn, struct ext4_extent_path *path) |
183 | { |
184 | struct ext4_extent_header *ehp; |
185 | uint16_t i; |
186 | int error, size; |
187 | daddr_t nblk; |
188 | |
189 | ehp = (struct ext4_extent_header *)ip->i_din.e2fs_din->e2di_blocks; |
190 | |
191 | if (ehp->eh_magic != EXT4_EXT_MAGIC) |
192 | return NULL; |
193 | |
194 | path->ep_header = ehp; |
195 | |
196 | daddr_t first_lbn = 0; |
197 | daddr_t last_lbn = lblkno(ip->i_e2fs, ip->i_size); |
198 | |
199 | for (i = ehp->eh_depth; i != 0; --i) { |
200 | path->ep_depth = i; |
201 | path->ep_ext = NULL; |
202 | if (ext4_ext_binsearch_index(ip, path, lbn, &first_lbn, |
203 | &last_lbn)) { |
204 | return path; |
205 | } |
206 | |
207 | nblk = (daddr_t)path->ep_index->ei_leaf_hi << 32 | |
208 | path->ep_index->ei_leaf_lo; |
209 | size = blksize(fs, ip, nblk); |
210 | if (path->ep_bp != NULL) { |
211 | brelse(path->ep_bp, 0); |
212 | path->ep_bp = NULL; |
213 | } |
214 | error = bread(ip->i_devvp, fsbtodb(fs, nblk), size, 0, |
215 | &path->ep_bp); |
216 | if (error) { |
217 | brelse(path->ep_bp, 0); |
218 | path->ep_bp = NULL; |
219 | return NULL; |
220 | } |
221 | ehp = (struct ext4_extent_header *)path->ep_bp->b_data; |
222 | path->ep_header = ehp; |
223 | } |
224 | |
225 | path->ep_depth = i; |
226 | path->ep_ext = NULL; |
227 | path->ep_index = NULL; |
228 | path->ep_is_sparse = false; |
229 | |
230 | ext4_ext_binsearch(ip, path, lbn, first_lbn, last_lbn); |
231 | return path; |
232 | } |
233 | |